Work-holding device for pipe-threading and like machines.



No. 886,613. PATENTED NOV. 20, 1906.

' -YM. H. SPEAR. WORK HOLDING DEVICE FOR PIPE THREADING AND LIKE MACHINES.

APPLICATION FILED 00124, 1904.

i v No. 836,613.

URRAY HiNoKLEY SPEAR'QF'LONDON, ENGLAND, ASSIGNOR TO UNITED STATES PATENT oFFIoE.

BARRINGTON ELLIOTT BURROVVES, OF LONDON, ENGLAND. WORK-HOLDING DEVKlE FOR PlPE-THREADING AND LIKE MACHINES.

Specification of Letteis Patent. i

Patented Nov. 20, 1906.

To all whont it concern." Be it known that I, MURRAY HINCKLEY I SPEAB, a subject of the King of Great Britain, residing at London, England, have invented an Improved Work-Holding Device for Pipe-Threading and Like Machines,of which the following is a specification.

The invention relates to an improved work-holding device for pipe-threading and like'machines of the character described in my United States patent application, dated October 23, 1903, under Serial No. 178,230, and will be readily understood by referring to the accompanying drawings, in which Figure 1 is a half-sectional side-elevation of such an apparatus adapted to be operated by hand and to which my improved work- 'holder has been applied. r Fig. 2 is a transverse section thereof on line a: y of Fig. 1 and Fig.3 is a perspectiveview of theimproved work-holder, shown separately.

In such an apparatus the pipe or the like 8 to be operated upon-is held in a work-holder formed of a series of separate segmental pieces 6, terminating at their rear end in a common externally-screwed ring 53. segmental pieces are on the exteriorprovided with one or, as shown Figs. 1, and 3, more inclined faces 7, adapted to engage with correspondingly-inclined faces on the. interior of a surround ng cylinder 9, in part internally threaded and adapted to be-screwed onto the threaded ring53 by means of a lever inserted in the tommy-holes 41, provided in the rear end of the cylinder 9, or by means of flats formed thereon or by other convenient means. The external surface of the cylinder '9 is unthreaded and fits within an outer fixed cylinder 3, provided at its forward end with an internal shoulder 52 against which flanges formed on the segmental pieces abut and to which by lugs 55, which fit into correspondingrecesses formed in the outer fixed cylinder'3, as shown, or by dowel-pins or other convenient means, they are held, so that they are free to expand and contract on the pipe or the like 8, but are prevented'fromrevolving when the surrounding cylinder 9 is screwed in'or withdrawn. l

The outer fixed cylinder 3 may be, as shown, provided with external threads of different pitch 25 57 with one or other of which difierently-thread'ed blocks 23 56, carcylinder The" ried on a rockingpiece 5 8, pivotally mounted at 59 in a bearing-bracket on an outer revoluble sleeve 1, carrying the tools, may be caused to alternately engage so that threads of different pitches-may e cut by simply throwing one or other of the blocks 23 56 into engagement with the threads 25 57 on the cylinder 3.

' In the machine illustrated the outer revoluble sleeve 1 is provided with extensions 14 15, which carry, slidably mounted thereon,

"respectively a screwing-tool 1 1 and a partingtool 32, and which tools may be interchangeable, or other tools may be substituted there for, and the tools may be adjusted, by means of a nut and screw 20, in any well-understood manner.

In operation the pi placed within the wor holder,' the segmento grip thework by screwing the cylinder 9 upon the screwed ring 53,- whereby the flanged ends of the gripping-pieces 6 are drawn against the shoulder 52 of the fixed 3, so that any slipping or. lateral movement of the pieces 6 which might displace the work is prevented, and they are given a direct contraction on the work by reason of the inclined faces 7 thereon contacting with the inclined faces on the interior. of the cylinder 9; According to the thread which it is desired to out upon the work, one or other. of the blocks 23 or 56 is rocked over about the pivot 59, into engagement with the respective threads 25 or 57 on the cylinder 3,

to which it corresponds, and is retained in engagement therewith by means of the locking pin 54, which passes through holes for the -p ose in the bearing-bracket 60 and the rod 'ng piece 58, carried by the tool-carrying sleeve 1. I On rotating the sleeve 1 therefor. by means of hand-levers 22, carried in sockets 21 on said sleeve or other means, the latter, and consequently the tool or tools, are traversed upon the work, which 1s held still in ro'ckingpiece 58 secured by the aforesaid pin 54 in its mid-position, (when neither block' will be in engagement with the cyline or other work 8 is tal gripping-piecesfi of which are contracted reached, in which position said sleeve may be I retained-tovrotate about the fixed cylinder 3 by tightening a nut and screw 26 upon a bar 28, slidable in'guides 29, carried by the sleeve 1, the end of said bar carrying a disk 28 adapted to travel round in a circular groove 30, formed on the rear end of/the cylinder 3.

Where pipes of large diameter are to be operated upon, gearing of any suitable form and driven from any convenient source of power may be substituted for the handpower levers 22 herein shown. In such apparatus the employment of a work-holdertof the improved construction described enables long lengths of pipe to be operated upon, inasmuch as the provision of more than one inclinedface on each segment insures a firmer grip being maintained over a large's'urface of the work and the prevention of any lateral movement of the wedges on the work by reason of the flanged ends thereof abutting against the shoulder 52 on the fixed cylinder when the segments are contracted by the screwing of the cylinder on the screwed ring 53 obviates any displacement of the work with respect to the tool, which is consequently always perfect adjustment therewith should it be necessary, for instance, to recut a thread already on the work, and a further advantage accrues from the means employed for enabling threads of different pitches to be out upon the work without the necessity which has hitherto obtained of detaching certain parts and substituting others therefor,

whereby a saving of both time and trouble is efiected."

In the apparatus above described it is possible to-first make the screwing-tool by fitting a metal blank in the place occupied by the tool and gripping the hob carrying the desired thread in the parts 6, so that the'rotation of the machine will cause the threaded hob to cut the thread on the blank to form the tool, which is an advantage, inasmuch as the thread on the tool thus made is in perfect union with the thread on the fixed cylinder 3, the blank having been traversed thereby through the sleeve, which carries it against the hob.

What I claim is- In awork-holding device for pipe-thread- I ing and like vmachines and in combination, segmental grippingieces having inclined faces thereon, a part or containing said gripping-pieces havingrecesses therein, a tubular stem uniting said gripping-pieces, projections carried by the grippingpieces and engaging the recesses in said containing part for preventing longitudinal, lateral, and rotative movement of the gripping-pieces, and means in engagement withthe inclined faces and I moving relatively thereto for forcing the latterdown upon the work.

In testimony, whereof I have hereunto set my hand inthe presence of two-subscribing witnesses. in

' MURRAY HINCKLEY SPEAR. Witnesses:

A. H. A FonD,

FRANCIS W. FRIGOUT. 

